摘要
Polyvinylidene fluoride (PVDF) continues to attract researchers in the field of membrane separation due to its many outstanding properties. However, fully modifying it into a multifunctional composite membrane with ultra-high stability remains a significant challenge. In this work, a uniform BiOBr-BiOCOOH/PVDF composite membrane was prepared by incorporating catalytic materials into the casting solution through an in-situ deposition method. The effects of different loadings of catalytic materials on the performance of the p-n heterojunction catalyst were investigated. The composite membrane surface was modified by self-assembling tannic acid (TA) and subsequent crosslinking, and its oil-water separation performance and resistance to acidic and alkaline conditions were evaluated. Using dyes, antibiotics, and oily wastewater as representative pollutants, the membrane’s rejection and catalytic capabilities were thoroughly analyzed, achieving average rejection rates of 95%, 86%, and 99%, respectively. The changes in the crystalline phases of PVDF molecules, the physical morphology, and the chemical structure of the composite membranes were thoroughly discussed. Catalytic studies demonstrated that the catalytic materials within the composite membrane possess highly efficient light absorption capabilities, achieving photodegradation rates of over 99% for various pollutants and over 98% for complex wastewater containing mixed dyes. The surface modification via self-assembly endowed the membrane with hydrophilic and oleophobic properties, resulting in high rejection efficiency for oil-in-water emulsions and excellent performance in separating oilfield industrial wastewater, along with strong self-cleaning ability. The study also highlights the composite membrane's adaptability in extremely acidic and alkaline environments, demonstrating its outstanding physicochemical structural stability.
危险品化学品经营许可证（带存储）